The present invention relates to an optical device module incorporated in digital cameras, camera phones and the like and having a solid-state image sensor for photographing a subject, and a method of fabricating the optical device module.
A solid-state image sensor provided in digital cameras, camera phones and the like is for capturing the subject to be photographed. The solid-state image sensor is integrated into a module together with a lens, an infrared intercepting material and a signal processor processing the image information captured by the image sensor, and is provided as an optical device module. In recent years, digital cameras, camera phones and the like incorporating the optical device module have been reduced in size, and the optical device module has also been reduced in size.
In the optical device module, it is necessary that the optical center of the pixel area of the solid-state image sensor coincide with the optical center of the lens, and it is also necessary that the plane formed by the pixel area be orthogonal to the optical axis of the lens. When the accuracy of the positioning of the lens with respect to the solid-state image sensor is low, a problem occurs such that focus cannot be achieved or that the image captured by the solid-state image sensor is dark. For this reason, an adjustment mechanism for adjusting focus is provided, and focus adjustment is performed after the optical device module is fabricated. However, the provision of the adjustment mechanism hinders the size reduction of the optical device module.
Japanese Patent Application Laid-Open No. 2003-110946 proposes an image sensor module package in which a solid-state image sensor is bonded onto a circuit board, a housing holding an IR filter is bonded onto the circuit board so as to cover the solid-state image sensor, and a holder holding a lens is fixed to the housing. The fabrication process is simplified by fixing the holder and the housing by press fitting.
Japanese Patent Application Laid-Open No. 2004-297282 proposes a camera module in which a holder holding a lens and an optical filter is fixed by a bonding agent onto a package where an image sensor is fixed. The holder is bonded by use of two kinds of bonding agents, a volatile curing bonding agent that cures by the volatilization of the solvent and an ultraviolet curing bonding agent that cures by the application of ultraviolet light, the lens position is adjusted after temporary bonding, and after the position is determined, the bonding agent is cured to thereby fix the holder. Since the position adjustment can be performed after bonding, the lens positioning accuracy can be improved.
Japanese Patent Application Laid-Open No. 2004-301938 proposes an optical device module in which a signal processor that processes signals outputted from a solid-state image sensor is bonded to a wiring board, the solid-state image sensor is bonded onto the signal processor, a transparent lid is bonded to a surface of the solid-state image sensor and a lens holder holding a lens is bonded to the transparent lid. Since the lens holder is bonded to the transparent lid bonded to the surface of the solid-state image sensor, the accuracy of the positioning of the lens with respect to the solid-state image sensor can be improved.